It is the purpose of the proposed project to assess the role of the sympathetic nervous system in the pathophysiology of experimental renal hypertension in the rat. This is to be achieved by attempting to produce different types of chronic renal hypertension in the rat totally deprived of sympathetic innervation. Permanent total sympathectomy will be produced in the rat by injecting the new-born animal with 6- hydroxydopamine. This procedure results in permanent degeneration of the sympathetic fibers. Different types of renal hypertension will be produced in order to determine the role of the sympathetic nervous system in different hypertensive models. In addition, the influence of total sympathectomy on renin production will be determined. The possible role of renin versus a nonspecific vasopressor factor of renal origin will be studied.